The present invention generally relates to scroll compressors, and more particularly materials used in scroll compressors from the viewpoint of thermal characteristics.
No prior art scroll compressors, have proposed the use of certain combinations of materials for the stationary scroll member, the orbiting scroll member and the Oldham's ring, with the combinations being determined by taking thermal characteristics into consideration. The nearest prior art proposal closest to the above proposal is disclosed in, for example, Japanese Patent Unexamined Publication No. 1-53084.
This publication discloses the art of varying the combination of the materials used to form the orbiting scroll member and the Oldham's ring, and the variation is effective for reducing the size and weight of the entire scroll compressor and assures improvement in sliding characteristic and sliding durability so as to enhance performance and reliability.
A scroll compressor has the following drawback particularly when the scroll compressor is of the high-pressure vessel type in which the compressor elements are in a high-pressure gas atmosphere for example, an atmosphere formed by the compressed gas to be discharged. Since the stationary scroll member and a frame supporting the member are exposed to a high-temperature, high-pressure atmosphere, conduction of heat through members such as the stationary scroll member and the frame may cause the gas suctioned into the compression chamber to be heated to an increased extent, thereby reducing the volumetric efficiency of the compressor. Furthermore, various members may become deformed due, for example, to the temperature distribution over the members or pressure acting thereon. In such cases, the specific volume of the gas or leakage from the compression chamber may be increased, thereby adversely affecting the performance of the compressor.